Am I understanding this (DPI)?

Here's the long and short of it. For ease of setup and use with new users we used to recommend (and still do in most cases) to set the mouse to maximum sensitivity and set the KeyMander value to match. This advice came at a time when most mice had a max resolution of around 5K, and entry level mice were around 2K max so setting the maximum resolution was important. Now most mice accomodate 10K+ resolutions, so it isn't as important to set to max. In fact, some games will benefit from a lower dpi setting if aim-assist is important to you. In these games, 3.5-5K works better to keep your aim-assist sticky. Now here's were it gets tricky; some games like Rainbow Six Siege and Overwatch have aim/look engines that are less refined than say the Call of Duty engine, so they benefit from 8K+ dpi settings to smooth them out as much as possible. In the end, it all boils down to the game you are playing and the capabilities of the mouse you have, so yes, I'd say you are on the right path.

Hope fully this works for me ?